:root {
  --bg: #0f0f15;
  --surface: #16161d;
  --text: #f4f4f6;
  --sub: #b7b8c2;
  --faint: #7c7d89;
  --accent: #8b5cf6;
  --border: rgba(255, 255, 255, 0.1);
  --maxw: 720px;
}

* { box-sizing: border-box; }

html { -webkit-text-size-adjust: 100%; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Hiragino Sans", "Noto Sans JP", "Segoe UI", Roboto, sans-serif;
  line-height: 1.75;
  -webkit-font-smoothing: antialiased;
}

a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }

.wrap { max-width: var(--maxw); margin: 0 auto; padding: 0 20px; }

header.site {
  border-bottom: 1px solid var(--border);
}
header.site .wrap {
  display: flex;
  align-items: center;
  gap: 10px;
  padding-top: 18px;
  padding-bottom: 18px;
}
.logo {
  font-weight: 800;
  font-size: 20px;
  letter-spacing: 0.3px;
}
.logo .mark { color: var(--accent); }
header.site nav { margin-left: auto; display: flex; gap: 18px; font-size: 14px; }
header.site nav a { color: var(--sub); }

main { padding: 40px 0 64px; }

.hero { text-align: center; padding: 56px 0 28px; }
.hero h1 { font-size: 32px; margin: 0 0 12px; letter-spacing: 0.2px; }
.hero p { color: var(--sub); font-size: 16px; margin: 0 auto; max-width: 520px; }

.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 22px;
  margin: 18px 0;
}

h1.doc { font-size: 26px; margin: 8px 0 4px; }
.updated { color: var(--faint); font-size: 12px; margin-bottom: 18px; }
.intro { color: var(--sub); margin-bottom: 22px; }

section.doc { margin-bottom: 18px; }
section.doc h2 { font-size: 16px; margin: 0 0 6px; }
section.doc p { color: var(--sub); margin: 0; white-space: pre-line; }

footer.site {
  border-top: 1px solid var(--border);
  color: var(--faint);
  font-size: 12px;
  padding: 24px 0 40px;
}
footer.site .wrap { display: flex; flex-wrap: wrap; gap: 14px; align-items: center; }
footer.site nav { display: flex; gap: 16px; }
footer.site nav a { color: var(--faint); }
footer.site .copy { margin-left: auto; }

@media (prefers-color-scheme: light) {
  :root {
    --bg: #eff1f4;
    --surface: #ffffff;
    --text: #14151a;
    --sub: #4a4b55;
    --faint: #8a8b95;
    --border: rgba(0, 0, 0, 0.1);
  }
}